That plate hasn't been used today so I think that most likely it's clean.
That plate should be clean since I don't think anyone has used it today.
ご質問ありがとうございます。
「そのお皿は今日はほとんど使ってないからまだ綺麗だと思うよ」は英語で「That plate hasn't been used today so I think that most likely it's clean.」と言います。
また、別の言い方ですが、「That plate should be clean since I don't think anyone has used it today.」でも言えます。
上記の２つの言い方は会話で自然に使えそうなので、どちらでも使ってみてください。
ご参考になれば幸いです。
I don't think anyone used that plate very much today, so I think it's still clean.
That plate has hardly been used today, so it should still be clean.
この場合、次のように言えます。
ーI don't think anyone used that plate very much today, so I think it's still clean.
「今日誰もそのお皿をあまり使ってないと思うから、まだ綺麗だと思う」
ーThat plate has hardly been used today, so it should still be clean.
「そのお皿は今日ほとんど使われてないから、まだ綺麗なはず」
ご参考まで！
I think that plate is still clean because we haven't used it much today.
こんにちは。
さまざまな言い方ができると思いますが、下記のような英語表現はいかがでしょうか：
I think that plate is still clean because we haven't used it much today.
そのお皿は今日はほとんど使ってないからまだ綺麗だと思うよ。
haven't used it much で「あまり使っていない」となります。
ぜひ参考にしてください。
アメリカ合衆国 
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